MV/LV Electrical Systems

MV/LV Electrical Systems involve the generation, distribution, transformation, and utilization of electrical power at medium-voltage (MV) and low-voltage (LV) levels. They are fundamental to industrial plants, commercial buildings, substations, power facilities, and infrastructure projects. MV systems are typically used to distribute electrical power efficiently over longer distances, while LV systems supply power to end-use equipment and smaller electrical loads.

MV systems generally include MV switchgear, transformers, circuit breakers, protection relays, busbars, cables, and metering systems. Electrical engineers are responsible for equipment selection, load-flow and short-circuit studies, protection coordination, cable sizing, voltage-drop calculations, and switchgear configuration. Transformers then step the MV voltage down to LV levels for utilization.

LV systems typically include main distribution boards (MDBs), sub-main distribution boards, motor control centers (MCCs), panelboards, cables, circuit breakers, contactors, and control equipment. Design activities include load estimation, feeder and cable sizing, breaker selection, voltage-drop and short-circuit calculations, earthing, power-factor correction, and protection coordination. Proper integration of MV and LV systems ensures safe, reliable, efficient, and maintainable power distribution, while allowing appropriate protection and isolation of electrical faults.